help you learn about yourself and how to get along with others
B.
show you a different aspect of the world
C.
give you a sense of belonging and a safe place to talk
D.
all of the above
Answer:
the answer would be d. all of the above
Answer:
-909.3KJ/mole
Explanation:
The heat of reaction is accessible from the heat of formation of reactants and products using the formula below:
ΔH = Σ ΔHf products - Σ ΔHf reactants
Before we proceed, it is important to know that the enthalpy of formation of element is zero ,be it a single element or a molecule of an element.
From the reaction for the formation of sulphuric acid, we know we need to know the heat of formation of sulphur (vi) oxide and water. The examiner is quite generous and have us for water already.
Now we need to calculate for sulphur (vi) oxide. This is calculated as follows:
We first calculate for sulphur(iv)oxide. This can be obtained from the reaction between sulphur and oxygen. The calculation goes thus:
ΔH = Σ ΔHf products - Σ ΔHf reactants
ΔH = [ 1 mole suphur(iv) oxide × x] - [ (1 mole of elemental sulphur × 0) + (1 mole of elemental oxygen × 0]
We were already told this is equal to -296.8KJ. Hence the heat of formation of sulphur(iv) oxide is -296.8KJ.
We then proceed to the second stage.
Now, here we have 1 mole sulphur (iv) oxide reacting with 0.5 mole oxygen molecule.
We go again :
ΔH = Σ ΔHf products - Σ ΔHf reactants
ΔH = [ 1 mole of sulphur (vi) oxide × y] - [ (1 mole of sulphur (iv) oxide × -296.8) + (0.5 mole of oxygen × 0)].
We already know that the ΔH here equals -98.9KJ.
Hence, -98.9 = y + 296.8
y = -296.8KJ - 98.9KJ = -395.7KJ
We now proceed to the final part of the calculation which ironically comes first in the series of sentences.
Now, we want to calculate the standard heat of formation for sulphuric acid. From the reaction, we can see that one mole of sulphur (vi) oxide, reacted with one mole of water to yield one mole of sulphuric acid.
Mathematically, we go again :
ΔH = Σ ΔHf products - Σ ΔHf reactants
ΔH = [ 1 mole of sulphuric acid × z] - [( 1 mole of sulphur vi oxide × -395.7) + ( 1 mole of water × -285.8)].
Now, we know that the ΔH for this particular reaction is -227.8KJ
We then proceed to to open the bracket.
-227.8 = z - (-395.7 - 285.8)
-227.8 = z - ( -681.5)
-227.8 = z + 681.5
z = -227.8-681.5 = -909.3KJ
Hence, ΔH∘f for sulphuric acid is -909.3KJ/mol
Answer:
0.01917 m^3/kg.
Explanation:
Given:
P = 15 MPa
= 1.5 × 10^4 kPa
T = 350 °C
= 350 + 273
= 623 K
Molar mass of water, m = (2 × 1) + 16
= 18 g/mol
= 0.018 kg/mol
R = 0.4615 kPa·m3/kg·K
Using ideal gas equation,
P × V = n × R × T
But n = mass/molar mass
V = (R × T)/P
V/M = (R × T)/P × m
= (0.4615 × 623)/1.5 × 10^4
= 0.01917 m^3/kg.
The specific volume of superheated water vapor under the conditions of 15 MPa pressure and 350°C temperature, using the ideal gas equation, is approximately 0.01919 cubic meter per kilogram.
The question is asking to calculate the specific volume of superheated water vapor using the ideal gas equation P = ρRT, where P is the pressure, ρ is the density (inverse of specific volume), R is the gas constant, and T is the temperature.
To find the specific volume (v), we need to rearrange the ideal gas equation to v = RT/P. Given that the pressure P = 15 MPa = 15000 kPa, the gas constant R = 0.4615 kPa.m³/kg.K, and the temperature T = 350°C = 623.15 K (adding 273 to convert °C to K), we can substitute these values into our rearranged equation balance to calculate for v.
The specific volume v = (0.4615 kPa.m³/kg.K * 623.15 K) / 15000 kPa = 0.01919 m³/kg. So, the specific volume of superheated water vapor under the given conditions is approximately 0.01919 cubic meter per kilogram.
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(2) Cd (4) Na
Answer: (3) In
Explanation: As the given compound is , it can be said that X has a valency of 3.
1)Barium (Ba): Atomic no: 56: : In order to complete its octet, it needs to donate 2 electrons, and thus the valency is 2.
2) Cadmium (Cd) : Atomic no: 48: : In order to complete its octet, it needs to donate 2 electrons, and thus the valency is 2.
3) Indium (In): Atomic no: 49: : In order to complete its octet, it needs to donate 3 electrons, and thus the valency is 3.
4) Sodium (Na): Atomic no: 11: : In order to complete its octet, it needs to donate 1 electron, and thus the valency is 1.
So the given element could only belong to the group containing Indium (In) as all the elements in the same group exhibit similar valency.
The first particles to evaporate from a liquid are those at the surface with the highest kinetic energy. These particles have sufficient energy to overcome the intermolecular forces of the liquid and become a gas.
The first particles to evaporate from a liquid are those at the surface of the liquid that have the highest kinetic energy. Evaporation is a process that occurs when particles at a liquid's surface have sufficient energy to break free of the liquid's intermolecular forces and become a gas, such as when water boils to steam. This is why sometimes we see a liquid seeming to 'disappear' over time, like a puddle drying up in the sun - it's the liquid evaporating.
Particles must have enough energy for the liquid to overcome the forces that are keeping them in the liquid. This energy is more likely to be found in particles at the surface, as they are not surrounded by other particles on all sides and therefore experience less resistance to their motion.
Learn more about Evaporation here:
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B) neutrons
C) electrons
Answer: Option (C) is the correct answer.
Explanation:
Each element contains three sub-atomic particles which are protons, neutrons and electrons.
Inside the nucleus of an atom, there will be only protons and neutrons. Whereas electrons revolve around the nucleus of an atom.
Protons have a positive charge, neutrons have no charge and electrons have a negative charge.
Thus, we can conclude that electrons are the subatomic particles and each of them have a negative electrical charge.